Therapeutic Targeting of Krüppel-Like Factor 4 and Its Pharmacological Potential in Parkinson's Disease: a Comprehensive Review

LRRK2 G2019S Mutated iPSC-Derived Endothelial Cells Exhibit Increased α-Synuclein, Mitochondrial Impairment, and Altered Inflammatory Responses

The blood-brain barrier (BBB) serves as an interface between the bloodstream and the central nervous system. It limits the movement of molecules and immune cells, regulates the entry of nutrients, and removes waste products from the brain. The dysfunction of the BBB has been identified in Parkinson's disease (PD) but the role of the BBB and endothelial cells (ECs) has not been well studied. LRRK2 G2019S mutation is the most common PD causing mutation with similar pathophysiology than in sporadic cases. How the mutation affects EC function has not been investigated previously in patient cells. In the study, we used iPSC-derived ECs from PD patients with the LRRK2 mutation as well as cells from healthy individuals. We report that PD patients' ECs have higher levels of α-synuclein and an decreased maximal and ATP-linked respiration and altered response to inflammatory exposure, especially to TNFα. In addition, transcriptomic analysis showed upregulation of fatty-acid-synthesis-related pathways in PD patients' ECs and the downregulation of lncRNA MEG3, both of which have been associated with PD. Altogether, PD patients' ECs manifest some of the PD-related hallmarks and are likely to contribute to the pathogenesis of PD.

Unraveling the Molecular Mechanisms of SIRT7 in Angiogenesis: Insights from Substrate Clues

Angiogenesis, a vital physiological or pathological process regulated by complex molecular networks, is widely implicated in organismal development and the pathogenesis of various diseases. SIRT7, a member of the Sirtuin family of nicotinamide adenine dinucleotide + (NAD+) dependent deacetylases, plays crucial roles in cellular processes such as transcriptional regulation, cell metabolism, cell proliferation, and genome stability maintenance. Characterized by its enzymatic activities, SIRT7 targets an array of substrates, several of which exert regulatory effects on angiogenesis. Experimental evidence from in vitro and in vivo studies consistently demonstrates the effects of SIRT7 in modulating angiogenesis, mediated through various molecular mechanisms. Consequently, understanding the regulatory role of SIRT7 in angiogenesis holds significant promise, offering novel avenues for therapeutic interventions targeting either SIRT7 or angiogenesis. This review delineates the putative molecular mechanisms by which SIRT7 regulates angiogenesis, taking its substrates as a clue, endeavoring to elucidate experimental observations by integrating knowledge of SIRT7 substrates and established angiogenenic mechanisms.

Mechanism of HDAC1 Regulating Iron Overload-Induced Neuronal Oxidative Damage After Cerebral Hemorrhage

Iron overload is associated with brain edema in the context of intracerebral hemorrhage (ICH). Here, we investigated the role of histone deacetylase 1 (HDAC1) in mediating oxidative damage induced by iron overload after ICH. Utilizing ICH mouse models and FeCl2-induced HT-22 cell models, we assessed HDAC1 expression and its impact on iron overload and oxidative damage. We examined the levels of Kruppel like factor 4 (KLF4), RAN binding protein 9 (RANBP9), as well as the acetylation levels of HDAC1 and histones H3 and H4 in the KLF4 promoter, and the KLF4 level in the RANBP9 promoter. Additionally, we investigated the binding relationships between KLF4 and the RANBP9 promoter, HDAC1 and miR-129-5p. Our results demonstrated elevated HDAC1 expression in ICH mice and FeCl2-induced HT-22 cells. HDAC1 silencing improved neurological function in mice, reduced brain edema, and alleviated iron overload and oxidative damage in vitro. HDAC1 downregulated KLF4 expression by reducing acetylation levels in the KLF4 promoter, leading to decreased KLF4 enrichment in the RANBP9 promoter and increased RANBP9 expression. Furthermore, upstream miR-129-5p inhibited HDAC1, and the downregulation of miR-129-5p mitigated the protective effect of HDAC1 silencing. Collectively, our findings highlight the significant role of HDAC1 in exacerbating iron overload-induced oxidative damage following ICH and its regulation by miR-129-5p.

A review of KLF4 and inflammatory disease: Current status and future perspective

Inflammation is the response of the human body to injury, infection, or other abnormal states, which is involved in the development of many diseases. As a member of the Krüppel-like transcription factors (KLFs) family, KLF4 plays a crucial regulatory role in physiological and pathological processes due to its unique dual domain of transcriptional activation and inhibition. A growing body of evidence has demonstrated that KLF4 plays a pivotal role in the pathogenesis of various inflammatory disorders, including inflammatory bowel disease, osteoarthritis, renal inflammation, pneumonia, neuroinflammation, and so on. Consequently, KLF4 has emerged as a promising new therapeutic target for inflammatory diseases. This review systematically generalizes the molecular regulatory network, specific functions, and mechanisms of KLF4 to elucidate its complex roles in inflammatory diseases. An in-depth study on the biological function of KLF4 is anticipated to offer a novel research perspective and potential intervention strategies for inflammatory diseases.

Bioinformatic Evaluation of KLF13 Genetic Variant: Implications for Neurodevelopmental and Psychiatric Symptoms

The Krüppel-like factor (KLF) family represents a group of transcription factors (TFs) performing different biological processes that are crucial for proper neuronal function, including neuronal development, synaptic plasticity, and neuronal survival. As reported, genetic variants within the KLF family have been associated with a wide spectrum of neurodevelopmental and psychiatric symptoms. In a patient exhibiting attention deficit hyperactivity disorder (ADHD) combined with both neurodevelopmental and psychiatric symptoms, whole-exome sequencing (WES) analysis revealed a de novo heterozygous variant within the Krüppel-like factor 13 (KLF13) gene, which belongs to the KLF family and regulates axonal growth, development, and regeneration in mice. Moreover, in silico analyses pertaining to the likely pathogenic significance of the variant and the impact of the mutation on the KLF13 protein structure suggested a potential deleterious effect. In fact, the variant was localized in correspondence to the starting residue of the N-terminal domain of KLF13, essential for protein-protein interactions, DNA binding, and transcriptional activation or repression. This study aims to highlight the potential involvement of the KLF13 gene in neurodevelopmental and psychiatric disorders. Nevertheless, we cannot rule out that excluded variants, those undetectable by WES, or the polygenic risk may have contributed to the patient's phenotype given ADHD's high polygenic risk. However, further functional studies are required to validate its potential contribution to these disorders.